Periscope Installed

I’ve been tardy posting updates this last week – been busy trying to get stuff back together for the new Clone Wars movie.

I finally got my periscope installed and functioning. Here’s a short video of it in action

There’s still some small quirks I need to iron out, but I’m pretty close to being done with it (for now). One of the big issues is that everything has to be align perfectly, and taking the dome on and off isn’t as simple as it used to be. What I’ve quickly realized is that with every gadget I add maintenance goes up exponentially.

I repainted the periscope housing after tweaking the curve at the top to match my dome. While I was at it I clean up some spot that I wasn’t happy with

Right now the dome pie panel velcro’s on top of the periscope, but it’s hard to get it to sit flush with so much spring in the velcro. It also very hard to align things perfectly and to get it to stay put. I’m probably going to use magnets instead or even use the small side screws I added. Right now they’re just for show to mimic the ROTJ periscope.

I’m not convinced that the clear lenses look correct either, it’s hard to tell but I suspect the original had a slight frosting to it.

I really need to document the wiring and micro-controller setup for this, but here’s a few overview shots of the periscope installed and there are more in the gallery.

Right now, up/down is manually controlled by the Futaba transmitter, at some point I’ll probably automate this. I also have a small 08M Picaxe micro-controller dedicated to automatically rotating the periscope when it’s fully extended. In addition I have to route 12VDC from the main dome power board back down to the periscope light circuit. The Picaxe and the small mini-servo that rotates everything runs on 5VDC and just taps off of the power for the lift servo.

There are two small micro switches, the first trigger the micro-controller to start randomly turning the periscope when it reaches the top

The second turns on/off the lights when the periscope is raised/lowered

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Posted by Chris on August 12th, 2008 in Dome, Electronics | 2 Comments

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More Periscope Work

I’m still fiddling with the periscope, I added some LEDs, a servo to make it turn and something to mount it to the lift mechanism.

But first I had to adjust the dome pie panel cut out to give more clearance. I marked off the area I wanted to cut and Dremeled in a few slots to start things off and finished it with a small hacksaw blade.

The main periscope assemble is mounted atop PVC tube to add more height.

I wanted to easily remove it for maintenance and also allow some height adjustment at the same time. This little tube is fixed to the lift mech

And the main PVC riser tube slips over and locks into place with a couple of screws

I installed a small HiTec HS-55 servo into the top of the PVC tube to turn the periscope side to side when it’s extended. Attached is a round plate the aluminum based of the periscope will screw into.

I’ve also add the LEDs to the main periscope housing. On the front is an array of 6 rectangular LEDs. These are very close to one’s used on the original ROTJ periscope

They’re glowing orange in the photo but they’re deep red in person. Power is 12V and no resistors needed as they’re in series

Here’s the block of LEDs soldered together before I installed them

I’ve wired in some bright white LEDs inside and some colored one’s on the back of the housing, I also re-appropriated one of my old PSI boards to blink a couple of LEDs to add a bit of variety.

Getting closer 🙂

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Posted by Chris on August 1st, 2008 in Body, Dome, Electronics, Feet | 3 Comments

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Lift Mech Support Bracket

I replaced the original drawer slider bracket with something a little bigger. It’s cut from a piece of alu angle and makes the whole setup a lot more solid. You can see the original bracket in the background.

The slots make it easy to align on the dome ring

I still need to work on the riser below the periscope assembly and fix it to the lifter.

Posted by Chris on July 24th, 2008 in Dome | 1 Comment

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New Periscope Lift Mech Prototype

I’ve been busy prototyping a new periscope lift mechanism for Artoo.

Some of you may remember my earlier posts and videos demonstrating a mechanism I’d purchased from Daniel, unfortunately I gave up on it a very long time ago. In my opinion the design was flawed from the start and I never did get it to work well, but not for the lack of trying on my part.

Now that I’ve finished adding servos to the dome I was anxious to get the periscope working. I remembered seeing photos of Wayne Orr’s lift mech and thought I’d try and do something similar. Rather than fabricate something new he uses a drawer slide as the basis for the design and a small motor to hoist the periscope up on a platform.

The only catch with Wayne’s implementation is that the periscope and life form scanner mechanisms extend deep into the droids body. I don’t have this luxury as I’ve left the top ring cross bar in place to support the slip ring. So anything I come up with would have to fit within the approximate 10″ height restriction of the dome. The periscope assembly itself is around 6″ tall, so that would be the minimum requirement but if I could get more height that would be a plus as I could add an additional riser or have room for a servo to rotate the periscope once extended.

I’d shopped around and bought a selection of drawer slides, but couldn’t find anything shorter than 16 inches locally. Once I had them on the workbench I realized that it really didn’t matter because whatever extended out would need to be hacked off anyway. In the end I picked a 20 inch slider made by KV because it’s two sliding components worked in lock step, which was important to my design.

I removed the stops and hacked it down to just over 10 inches and cut a small section of the inner slider that would run up and down on the sliding bearing, which itself ran inside main track.

This is the start point with the slider on the right

And it extended all the way to the left. Notice the two part slider has moved and not just one piece.

http://www.artoo-detoo.net/gallery/v/build/gadgets/IMG_1339.JPG.html?g2_imageViewsIndex=3

Unfortunately I have to jump a few steps as I didn’t take many photos of my late night tinkering with the lift platform and various iterations of how I tried to move it.

I’d originally added a roller to the top (similar to Wayne’s) which would guide the rope, but in the final design it wasn’t really needed – and currently acts as the end stop.

Right now I have a fixed motor on the lift platform that pulls itself up with a piece of string attached to the top of the slider. It uses gravity to lower itself back down as the motor unwinds the string.

I’m using a small Vex motor, but basically it’s a servo that can continuously rotate, so I can plug it directly into my receiver without the need for a speed controller.

It looks like the platform is sloping in this photo, but I’m hoping it’s just the angle of the shot 🙂

Here’s a short video of it in action

I have a lot more work to do on this and not sure how well it will work inside Artoo, especially at an angle. My short list of things to work are:

  • Add support to help stop the drawer slide shaking.
  • Extra weight to the platform to help it lower.
  • Make sure it’s all level
  • Limit switches to stop the motor
  • Possibly automate with the PICAXE micro-controller, rather than control it manually via the Futaba transmitter.

In closing I also wanted to mention that I’d experimenting with having a spring loaded wheel on the motor (same position as it is now) that would run along the side of the drawer slide to pull the platform along. I still like the idea and may give it another try later. It definitely had a smoother action and having a wheel on the motor made the lift a little faster – Unfortunately I couldn’t get the spring mechanism to work right.

Posted by Chris on July 22nd, 2008 in Dome, Electronics | 10 Comments

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Periscope Port Detail

Here’s something else I’d forgotten I’d worked on before C4 and not posted.

The original dome periscope had a small raised lip around the side ports/windows. Neither my PVC or aluminum periscope kit has this so I improvised.

I used a 1″ Nylon gasket from the plumbing department at my local Ace Hardware store, and just superglued it in place. However, paint has a real hard time adhering to Nylon, so if I was to do this again I’d probably try and find an O ring made from something different. Also if you try and rough up it up you’ll get fine strands that will never go away.

I guess I’m posting this as an idea rather than a solution.

Posted by Chris on January 11th, 2008 in Dome | 1 Comment

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Periscope LEDs and RoboteQ

Not a whole lot going on. I did find a very cool surplus electronics store this week in Santa Clara called HSC. They carry a LOT of stuff at a fraction of the cost and the place is full of things that can be used on R2. I was hoping to find a slip ring to experiment with but I was out of luck. I did pick up a few bits though, including some red rectangular LEDs for the front slot on the periscope.

I did a quick test fitting on my aluminum periscope housing and they fit perfectly.

There’s very little published reference material for the periscope, but I have it on good authority that the front red light was made up of 6 of these LEDs.

I also worked a bit on my RoboteQ speed controller, adding a RS232 connection to the provided PWM cable to allow me to monitor things live from a tethered laptop. Basically I ran two wires (RxD/GND) from the 25-pin plug they provide to a 9-pin RS232 plug/housing.

The plug you see on the right may look like an RS232 connector, but it’s really used to connect just two PWM wires from the Vex receiver into the RoboteQ. It comes as standard with the controller, and they also provide a seperate RS232 cable to connect your computer. I really don’t understand why they don’t just provide one combine cable. Confused? Please see the RoboteQ manuals 🙂

Once the controller is connect to my computer I can use they’re monitoring software called roborun. It polls the speed controller and graphs live data like battery voltage, controller temperature, current being used, PWM data etc. It also allows me to exercise the motors without using my RC transmitter.

Posted by Chris on January 10th, 2008 in Electronics | 2 Comments

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Thinking about dome electronics placement

With all the dome work yesterday I had time to think about it’s electronics and how I’m going to lay things out.

I’ve seen some people bond the dome ring to the dome, but I don’t think it’s such a good idea for me. For one I’m using the dome base plate that supports the periscope, and I’m thinking I’ll attach other things to it as well. The base plate is also bigger than the ring and it restricts access from the underside, so there would be no way to get in and fix a lot of things.

So the dome will split in two and I know have the dilemma that I’ll need decide where to put some things, either in the base or up in the dome, and then worry about running wires. For example, only the lift mech needs to attach to the dome plate, and it makes sense to put the weighty batteries down there too.

Initially the dome will contain the following this that are powered

  • Power Distribution Board – 12v in, 9v, 6v, 12v out
  • Front Logic -9v
  • Rear Logic – 24v
  • PSI’s- 9v x 2
  • Holo Projector Lights – 12v x 3
  • Vex Controller for Periscope Lift Mech – 6v
  • Batteries – 2 x 12v
  • Lift Mech Speed Controller – 12v

Later on I’ll be adding a few servos attached to the panels.

I think I’m going mount most everything on the dome base plate and run 3 power lines up into the dome with quick release.

Here’s a rough idea on layout

R2 Dome Electronics Rough Layout Idea

Posted by Chris on May 7th, 2007 in Dome, Electronics | 6 Comments

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Day of the Dome

Today was dome day…. Actually it was almost the entire weekend, but “Day of the Dome” sounded so much better than “Dome Weekend”.

I’ve made a lot more progress in the last few days and more confident that I can get the dome glued together in the next week or so ready for C4.

I’ve had a long list of to-do’s for the dome and been putting things off waiting for other bits to fall into place. The frame was holding me up for the longest time. Now that it’s pretty much done I could go back and work on the dome.

I installed Rockler bearing a week ago and it’s working great now after a few tweaks. One of the issues was the damn dome ring again. I thought I’d seen the last of problems with it, but the inner circle that’s tack welded on the inside is all warped/wavy so when I put it on the bearing the dome ducks up and down as it spins. Luckily I had to bolt the periscope life mech dome base plate to it and it helped level it off. It still needs tweaking but I’ll wait till the I have the skins on.

On Friday night and Saturday morning I decided to tackle fixing a wiring problem in my periscope lift mech rather than sending it back to Daniel. He kindly offered to fix it but it would mean that I would be delayed again from working on dome stuff.

I removed and disassembled the Delrin block holding the switches on Friday night, and a quick test showed that diodes had blown. I had to wait till Saturday morning for Radio Shack to open, but the good news was the new diodes were only 89 cents and about and 30 minutes work to get installed.

Next up was a bunch of fixes to the holes I’d cut in the inner dome a few months ago. When I first cut them I had the older aluminum Holo Projectors and resin Front and Rear Surrounds. Well now I have new HP’s and aluminum Surrounds, and everything was a tad bit bigger and I needed to tweak the holes.

I used a bottle wrapped in sandpaper to widen the HP holes.

Enlarging the HP hole

I also had to adjust the hole for the new Rear Logic.

Notice I’ve yet to cut the rear panels from the dome. I’m still using them as a guide to make sure everything while line up with the holes on the inner dome. I’ll probably cut them out this week now that I’m happy with the fit.

Next up was the dome ring. I needed to cut some notches in it to allow the PSI and HP’s to sit flush with the dome. I marked, dremel and filed out where I needed to the space.

I decide to tackle the periscope housing next even though I have a new aluminum one coming in the next few weeks. The PVC kit was still in pieces on my workbench but I really needed it to figure out how much bigger I needed to make the dome pie panel hole I’d miss sized a few months ago. So I quickly tacked it together with super glued and installed it on the now working lift mech.

Once done this allowed me to go back and adjust the dome pie panel hole that was too small. This is a real bad picture, but I’m trying to show that the periscope now passes through the opening without any problem. I’ll try and take some better pictures tomorrow.

At this point I almost started to cut the remaining holes in the dome, but decided to finish the PVC periscope kit and add a lens. I’d already done a lot of work on it in morning and I was so close to getting it done. Finishing it up would have two advantages, 1) I can make sure that it really does fit after squaring off the edges, and 2) if the aluminum one is delay at least I have a backup for C4.

For the lense I cut out a small square of acrylic and then rough sanded it into shape with my bench sander. I really should have used a thicker block, but all I had was 1/8″ acrylic. It really didn’t take long, so I may go back and make another later this week.

The fit was good

Next I marked out where I needed to sand down on the bench sander. Please be careful that you don’t push your fingers into the disk!

Here it is after I’ve sanded down the edges. Not pretty but I wanted to show how you can go from rough piece of plastic to something shiny in a matter of moments.

Here it is after some quick sanding through various grades of paper

And then polished up on my bench grinder with a polish wheel.

Next up was sanding and bondo’ing the housing ready for painting.

Almost done. I applied a layer of undercoat, sanded and undercoated again.

In the morning I’ll probably sand an prime again before trying the top white coat.

I also need to glue and pain the resin riser pieces, but I should be done tomorrow night. I can then think about adding the LEDs.

Posted by Chris on May 7th, 2007 in Dome, Electronics | No Comments

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